Bitfinex made the news last week after paying over $23 million in Ethereum (ETH) gas fees to transfer $100,000 in Tether (USDT). A few days later, the miner who won the block returned almost all of the ETH paid for the transaction.
Observers first noticed the transaction on Etherscan, where the transfer was using a Bitfinex wallet. Over the next few days, more information about the transfer emerged. Original reports suggested the gas fee was a typo by someone at Bitfinex, but according to Bitfinex this was not the case.
Decentralized finance (DeFi) firm DeversiFi took the blame: "At 11:10 UTC on the 27th September a deposit transaction was made using a hardware wallet from the main DeversiFi user interface with an erroneously high gas fee." So it was a software error, not a typo, and it came from a DeFi firm using a Bitfinex wallet, not Bitfinex itself.
DeversiFi offers "gas free" transactions to users, but it's obvious now that the company pays gas fees to operate on the Ethereum network. DeversiFi originated in Bitfinex's incubator, and it still uses a Bitfinex wallet.
A few days after the famous transfer, the miner gave back most of the 7626 ETH reward. It's unclear why the miner felt compelled to return the money.